Not sure if noise is timing chain issue...

[CMF_zipper]

Hi!

I have a 95 Micra (K11 3-door), and suspect a timing chain issue, but having not heard timing chain issues before I'm not sure.

Just after starting the car, before take off, when the car is idling, about 95% of the time there is a definite rattle within the engine. It sounds like a consistent tapping at about .5 second intervals. As soon as I drive off the rattling stops and it is quiet, zippy, and smooth when driving around.

If the chain was loose, wouldn't the noise be louder when driving if the chain was whacking the engine harder and faster? That's what confuses me, is why is it only rattly when idling? It also rattles more cold than when warm, but not always. When we got it, the previous owners had overfilled the oil and it was very black and mucky, so we did an oil change right away with high quality stuff for Japanese cars. This didn't help much. Perhaps it is a tensioner issue?

If anyone has any experience with this sort of issue (I know that timing chain issues are common in Micras), or how I can diagnose or tests to run to narrow down the issue, it would be very much appreciated!

Thanks guys!

 

[CMF_deNs]

Depending on the oil used and the condition of the chain, a refresh of new oil can make it a bit quieter but most likely not.

You should only hear it when it's idling and when putting some load on it or even revving it in neutral it should not be heard if it's not too severe. The only reason I could think it'd be like this is because the hydraulic tensioner has higher pressure in it and takes up the slack in the chain or that the slack is taken up in some other way.. don't know but it's a theory.

From what you've described above, I wouldn't be too concerned - sounds like any other micra with the chain noise. I you can take a video or audio sample of it then we can know for sure, but I'd say you're pretty safe.

---dens

 

[CMF_zipper]

Thank you for the reply!

I just found the timing chain diagnostic tool in the articles section. Looks like I need to remove the belts to isolate the sound. It sounds like noise only at idol is a bad thing though... on no...